This invention relates generally to strip coilers or uncoilers and more particularly to tension reels for cold strip coilers having an expansible mandrel which engages the eye of a coil after several original wraps have been made.
A single mandrel tension reel is generally used at the delivery end of a cold strip reduction mill for strip coiling. The use of such single mandrel tension reels for coiling strip in modern cold strip reduction mills presents a number of problems which are mainly due to the weight of the coils to be handled and also to the high speeds at which the strip issues from the mill. First, excessive time is required to remove the finished coil from one end of the tension reel. Secondly, mandrel deflection is experienced due to excessive forces over the mandrel length which can create defects in the coil and impose undue wear on the mandrel bearings which support the mandrel at one end. In this regard, when excessively heavy coils are being wrapped on the tension reel, it is also necessary to provide an outboard bearing support on the normally unsupported end of the tension reel mandrel. In addition, expensive heavy duty mandrel bearings are required to support the coil.
Conventional tension reels also require the use of expensive coil stripper equipment to remove the coils from the tension reel mandrel for further processing. Furthermore, where coil sleeves are used, considerable valuable time is consumed in mounting the next sleeve into position endwise over the mandrel. All of the foregoing disadvantages obviously reduce the production efficiency of the cold strip reduction mill and require the expenditure of additional initial capital outlay. It is a principle object of the present invention to eliminate or at least minimize all of the aforesaid disadvantages of the tension reels for strip coiling of the prior art.